Not content to cover 26.2 miles in a neat loop, Patrick Makau of Kenya turned the Berlin Marathon into his own personal conga line Sunday while setting a world record of 2 hours 3 minutes 38 seconds.

Just before Mile 17, Makau swung from one side of the flat course to the other, once, twice, three times, then surged. This zigzagging tactic exposed and dropped the previous record-holder, Haile Gebrselassie of Ethiopia, who had run 2:03:59 in Berlin in 2008.

The race kept growing more futile for Gebrselassie, who did not finish. He stopped briefly after Makau’s swerving and then again for good just before 22 miles, experiencing a surprising and debilitating flare-up of exercise-induced asthma, his agent said.

Gebrselassie also dropped out of the New York City Marathon after 16 miles last November, citing a knee problem. He briefly retired, then reconsidered, but will again be forced to confront his athletic mortality.

While Makau, 26, became an early men’s favorite at the 2012 London Olympics, Gebrselassie’s stirring international career — considered by many the greatest ever — appears to have reached irreversible decline. At 38, he seems to have set his last world record and surrendered to emerging runners who might soon cover the marathon in less than 2:03. That time would have been unthinkable a decade ago.

“A new generation is coming that is running very well,” said Makau, who averaged 4:43 a mile and shaved 70 seconds off his previous best, 2:04:48, which was run at the 2010 Rotterdam Marathon.

I am really looking forward to next year's London Olympics and the marathon.